Subbing photographic film



March 8, 1938. s, BABCOCK 2,110,496

SUBBING PHOTOGRAPHIC FILM Filed Feb. 26, 1956 IIYDROLYZED CELLULOSEACETATE AND RESIN CELLULOSE ORGANKZ DERIVATIVE SUPPORT EMUL8ION GELATINAND CELLULOSE ESTER GELATIN-RESIN-CELLULOSE ESTER MIXTURE GELATIN YZEDCELLULOSE ACETATE AND RESIN ORGANIC DERIVATIVE SUPPORT BY W 1 fw/W' 68 MI/M'zZ ATTORNEYS.

20 such treatment. I with a'layer of gelatin, resin, and a cellulose 2030 ments of the fire underwriters. a synthetic resin. The hydrolyzedester is one 30 Patented Mar. s, 1938 2,110,496

UNITED-f STATES-PATENT OFFICE -c I SUB I S IiNG rno'ioonarnlc FILMGeorge SQ BabcockQ Rochester, N. Yaassig nor, by

mesne assignments, toEa'stman, Kodak Company, Jersey 'City, N. J's-corporation ot'New ',Jfil'sgy'. y- ,.g.-j 4 1 v ppn a i6 euary-26,1936, Serial No. 65,873 v 10 was. (01. 95-4 v This inventionrelates to photographic mawill appear from the following description ofmy terials, and, moreparticularly, to methodsi'fo'r invention? I vapplying light sensitive emulsions to cellulose I have found that alayer of a cellulose ororganic ester film supports. 1 ganic ester may beapplied to a cellulose organic It is well known that a gelatind-silverhalide ester film base to which it would' not ordinarily 5 emulsioncannot be applied directly to a cellulose" adhere by mixing with it asynthetic resin, such organic derivative film 'support'A number of asacetone soluble glyceryl' phthalate. I have intermediate or'sublayersfinust be applied bealso found that the subbing properties of aceltween the support and the emulsion and each of lulose organic esterwhich ordinarily adheres to these layers must adhere to the layeradjoining the film base may, be-improved by mixing it it. The degree ofadhesion of the layers must be with gelatin and a synthetic resin inproper properly controlled in order to avoid the formaamounts. 7 tion ofa product which is brittle or in which In the accompanying drawing whichillustrates the layers peel from the support. If the adhesion inenlarged sectional views three types of film is too great, the film isbrittle and the layers crack made according to my invention, Fig. 1shows a 15 when the film is bent. If the adhesion is too film in which acellulose organic derivative supslight the layers are likely to peel orstrip from port is coated with a layer of hydrolyzed cellulose thesupport when the film is treated in the deacetate and resin; Fig. 2shows a film in which veloping or fixingbaths or when it is dried aftera cellulose acetate propionate support is coated One method of avoidingthese undesirable re organic ester; and Fig. .3 shows a film similar tosuits in a photographic film is to coat the cellulose thatof Fig. 1 inwhich both sides of the support organic derivative support with a layer,of anare subbed and sensitized. other ester, such as cellulose nitrate,to which According to the preferred form of my inventhe gelatin or other'subcoating layers may be tion a film support of-a cellulose organicester,

made to adhere. This method, however, has the which may be celluloseacetate or cellulose acedisadvantage that it introduces an inflammabletate propionate, is coated in any suitable manmaterial into the film andproduces a product her with a mixture of a hydrolyzed cellulose which,in many cases, does not meet the requireester, such as hydrolyzedcellulose acetate, and

In t e D O app of G y, e which has been hydrolyzed to such an extentthat No. 1, filed Ja y 1935, a method has it is not compatible with theester of which the b n p op s d for subbing cellulose organic estersupport is made andwould not adhere to it. The film base and avoidingthe use Of cellulose nitrate resin may be any suitable synthetic resin,p05- layers which Co p i pp y example, sessing adhering qualities forthe base such as 35 a Cellulose acet Dropionate film 198558116065"acetonesoluble glyptal or polymerized vinyl ace- Siv ly hy olyzed layersof'cellulose acetate pr0 tate. This subcoat is followed by the usualgelap one of the more hydrolyzed layers thus tin layer and thesensitized emulsion layer. The applied is of a Compositmn to which agelatin following examples illustrate several methods of 40 bingsolution can be made to adhere, whereas the producing a fil according tomy invention 40 gelatin layer would not adhere to a less hydrolyzedester. This method requires the application of Example 1 at least threeundercoating or sublayers to the support. A film: base of celluloseacetate propionate Itisan object of the present invention to'overwhichhas been slightly hydrolyzed and has a 45 come the above mentioned priorart dimculties propionyl content of,16% and an acetyl conand toprovide'a method for reducing the number tent of 29%,"is lead through animmersion type of sublayers required to afiix a gelatinemulsion hoppercontaining the following solution of celto a cellulose organicderivative film base. Anlulose' acetatehydrolyzed to such an extent thatother object is to provide a subbing method which its precipitationvaluexis about 69%: 5o

avoids the use of cellulosenitrate or other in.- y Y Grams. flammablematerial in a photographic film. A' Cellulose acetate; -l. 6- furtherobject is to provide a subbing method Ethyl alcoho1 40" which does notresult in a brittle productvor one Acetone 160 having loosely adheringlayers. Other objects Glyce'ryl-'-phthalateresin'(Glyptal) rr 3 55" Thissolution is coated. at a linear speed of approximately three feet perminute. The film is then-lead through an appropriate drying appara- -tuswhich is maintained at a temperature. of

approximately 120-300 1"., where the solvent is evaporated from thesurface of the material. The resin and ester coated material is thencarried through a second immersion hopper containing a gelatin solutionof approximately the following composition which is coated directly onthe resin and ester layer:

. Grams Gela in 1.2 Acetic a 7 0.12 Acetone '70 Water m Ethyl alcohol22.6

The gelatin coated material is then dried at appropriate temperaturesafter which the usual gelatin silver halide emulsion is applied upon thegel surface by known technic. thuscompleting the film.

Example I! A film base of, cellulose acetate, which has been hydrolyzedto such an extent that its precipitation value is about 90%, is leadthrough an immersion type hopper containing the fol lowing celluloseacetate and resin, solution in which the cellulose acetate has beenhydrolyzed to such an extent that its precipitation value c is about69%: l

' l Grams Hydrolyzed cellulose acetate '6 Ethyl alcohol 1 4O Acetone a158 .Glycerylephtha-lateresin." 2

This coating is dried and followed by the gelatin solution andgelatino-silver halide emulsion as described the preceding example. I

ample m 'A fully esterifiedcellulose acetate propionate film base whicha precipitation value of -96% is lead through an immersion hopper asdescribed in the preceding examples and' is coated with the followingresin and hydrolyzed cellulose acetate solution in which the celluloseacetate has a precipitation value of about 69% Grams Hydrolyzedcellulose acetate I 6 Ethyl alcohol 40 Acetone 156 Glyceryl-phthalateresin 1 1 complished by the presence of the resin in the.

coating, since withoutthe resin, the film showed objectionablebrittleness. This coating is dried in the usual way and is followed byasub of gela-, tin and cellulose ester, and the gelatino-silver halideemulsion.- The following examplesillustrate a method ofmaking a filmaccording to this modification ofmyinvention:

' Cellulose acetate propionate 5 This coating is dried in an appropriatemanner Example IV I A film base of a cellulose acetate propionaiehydrolyzed to such an extent that the propionyl content is 16% and theacetyl content 29% is coated with a solution of cellulose acetate pro- 5Gelatin a5 Cellulose acetate propionate 12 Glycerylfphthalate resin 8This coating is dried and is followed by a solution of gelatin andcellulose acetate propionate of the same composition as that used in thefirst coating and applied from any suitable solvent. The solid contentof this coating is as follows:

Percent Gelatin 06 and is followed by theusual gelatino-siiver halideemulsion, which is coated by known technic to complete the film.

E'mmple V A film base of cellulose acetate propionate having acomposition similar to that described in the preceding example is coatedwith a solution of hydrolyzed cellulose acetate having an apparentacetyl content of 39%, mixed with gelatin 'and a synthetic resin. Thesolid content of this solution is approximately as follows:

7 Per cent Gelatin 93 Cellulise acetate propionate 4 Glyceryl-phthalateresin 3 Cellulose acetate propionate 15 This coating is dried in anappropriate manner andcoated with the usual gelatino-silver halideemulsion.

'My invention will now be described by reference to the accompanyingdrawing. As illustrated therein Fig. 1 shows a film made according tothe preferred embodiment of my invention in which i0 is a film supportof a cellulose organic derivative and is coated with a layer ii ofasynthetic resin and a hydrolyzed cellulose ester such as hydrolyzedcellulose acetate which is in compatible'withthe ester of which thesupport is made, but compatible with the resin with which it is mixed.This layer is dried as described in thepreceding examples-and isfollowed by a gelatin layer I2 and an emulsion layer l3.

InFig. 2 which illustrates afilml romeo a- A cording to .thesecondfmodification of invention inwhich a support .of cellulose acetate.propionate is coatedwgwith a layer ll of gelatin. synthetic resin, anda cellulose ester which is a compatible with the ester'of which thesupport is made; This is followed by a layer II (if-gelatin 1 a'nd' -acellulose ester and on top of this is coated the usual gelatin layer l3.The -film shown in Fig. 31s a duplitized or double-coated film having acellulose organic X-ray photography.

My invention is applicabletethe -subbing b: any type of celluloseorganic ester film base, such as a, fully esterified or hydrolyzed mixedester,

' for example, cellulose acetate propionate or cellulose acetatebutyrate, or, a simple ester, such as hydrolyzed cellulose acetate. Theesters used in the subbing layers may also be, of any composition whichmeets the requirements of compatibility or lack of compatibility asdescribed above.

Among the artificial resins which may be used according to my invention,a great many materials are available. These include the polyvinylesters, such as polymerized vinyl acetate which is known, for example,under the trade name Gelva, the preparation oi! which is described inthe U. S. Patents No. 1,241,738; No. 1,586,803 and No. 1,710,825. Afurther type of resin which may be used is the polyvinyl acetal type.These resins are condensation products' of partially or completelyhydrolyzed polyvinyl acetate and an aldehyde such as formaldehyde,acetaldehyde, or butyraldehyde and are known as polyvinyl acetals. Theyare sold under various trade names such as Formvar, and Alvar, thepreparation of which is described in Br. Patent 351,082 and in U. S.Patents Nos. 1,955,068 and 1,990,399. A still further typeof resinwhiclLI may use are the alkyd resins, which are condensation products ofa poly-basic acid and a polyhydroxy alcohol. An example of this type ofresin is "Glyptal, which is a condensation product of glycerin andphthalic acid or phthalic anhydride. A still further type of resin isthe group known as the Santolites which are condensation products offormaldehyde with aromatic sulfonamides.

Ihave referred to the precipitation value of I a number of celluloseesters in the description of my invention. Precipitation value is thecustomary test which is used to determine the degree to which acellulose organic ester has been bydrolyzed. It is carried out asfollows for testing a cellulose acetate:

Five grams of thedry cellulose ester are accurately weighed and placedin a wide mouth 12 oz. bottle. To this are added 10000. of acetone(commercial grade of 99% orv better), the mixture is stirred untilhomogeneous. (The bottle should be closed during the stirring with arubber stopper fitted with a shaft for the stirrer.) To this dope isadded slowly from a pipette and with thorough stirring, 150 cc. of amixture consisting of 2 parts of distilled water and 1 part acetone byvolume. keep the solvents and mixtures at 20 C. wherever volumes arebeing measured. 1

At the end of the addition of the acetone water mixture, a mixture isobtained containing" 40% water by volume (neglectingcontraction).

in which is suspended the precipitated ester. This is allowed to standfor 12 hours at 2071C. At the end of this time precipitation has reachedequilibrium and proceeds no further, and during the same time settlingof the precipitate occurs.

25 cc. of the clearest portion (supernatent solu- Care should be takento the support, .a gelatin layer, and a light-sensitive emulsion layer.

tion) are removed with a pipette. This 25 cc. is centrifuged instoppered bottles at high speed until the liquid is perfectly clear.Exactly 5 cc. of the clear liquid are removed with a pipette andevaporated to dryness on a tarred watch glass. It W is the weight of theresidue in grams the precipitation value which equals the per cent.ester precipitated,

properties when subjected to the usual tests which are described forexample in my prior application Serial No. 27,409, filed June 19, 1935.The degree of adhesion of the sub layers according to my presentinvention is controlled by the composition of the cellulose ester and bythe proportion or ester to resin. It is not necessary to rely on thestrength oi. the solvent and its action on the film base in order toobtain layers which adhere in suificient degree to the base. A furtheradvantage in the use of a cellulose ester layer directly over the filmbase is that it seals in the plasticizer which is ordinarily containedin the film base, and therefore results in a better surface to which toapply the following gelatin-containing subbing solutions.

I claim:-'

1. A photographic element comprising a cellulose organic ester support,and in order thereon, a layer comprising a mixture of a. synthetic resinselected from the group consisting of polyvinyl resins and alkyd resinsand a hydrolyzed cellulose organic ester, a, gelatin layer, and anemulsion layer.

2. A photographic element comprising a cellulose organicester support,and in order thereon, a layer comprising a mixture of a synthetic resinselected from the group consisting of polyvinyl resins and alkyd resinsand a hydrolyzed cellulose organic ester which is incompatible with thesupport, a gelatin layer, and an emulsion layer.

3'. A photographic element comprising a cellulose organic ester support,and in order thereon, a layer comprising a mixture of a synthetic resinselected from the group consisting of polyvinyl resins and alkyd resinsand a hydrolyzed cellulose organic ester, a gelatin layer, and alight-sensitive emulsion layer.

4. A photographic element comprising a cellulose organic ester support,and in order thereon, a, layer comprising a mixture of a, syntheticresin selected from the group consisting of polyvinyl resins and alkydresins and a hydrolyzed cellulose organic ester which is incompatiblewith 5. A photographic element comprisingza cellulose organic estersupport, and in order'there- -on, a layer comprising a mixture ofasynthetic resin selected from the group consisting of polyvinyl resinsand. alkyd resins and a hydrolyzed 1 cellulose organic ester, a gelatinlayer, and a gelatino-silver halide emulsion layer.

' 6. A photographic elementcomprising a cellulose organic ester support,and in order therevinyl resins andy'alkyd resins and a hydrolyaed' on, alayer comprising a; mixture of a-synthetic resin selected i'rom thegroup consisting of poly cellulose organic ester which ls-incompatiblewith the support, a gelatin layer, and halide emulsion layer.

7. A photographic element comprising a fully esterifled celluloseorganic ester support, and in order thereon, a layer comprising amixture 10! a synthetic resin selectsdiirom the group consisting ofpolyvinyl resins and alkyd resins and a hydrolyzed" cellulose organicester which is inf compatible with the support, a gelatin layer, and j agelatino-sllverhalideemulsion layer.

8. A photographic element comprising acellulose organic mixed estersupport, and in order thereon,, a layer, comprising a mixture 01'asynthetic resinfselected from the group consisting of polyvinyl resinsand alkyd resins and, a hy- 20 drolynedcellulose organic ester which isincoma gelatino-silver patible with the support. a gelatin layer, and ai gelatino-silver halide emulsion layer.

9. A photographic element comprising a 0G1? lulose acetate propionatesupport, .and-in order thereon, a layer comprising a mixture of asynthetic resin from the group conlilting or polyvinyl resins :and alkydresins and a by:

cellulose omnic'ester which i'sj incompatible with the who; a gelatinlayer, anda geiatino-silver halide emulsion layer. p 10. A photographicelement comprising accllulose organicmixed eater-support, and in' orderthereon a layu' comprising a mixture or a synthetie resin selectedfrom'the group consistins o! P lyvinyl resins and alkyd resins andahydrolysed cellulose acetate propionate which is incompatible with thesupport. a gelatin layer,and a gelatino-silver halide emulsion layer.

